In the prior art, it is known to disperse particles or fibers of polytetrafluoroethylene, or other water-insoluble materials in an electroless nickel plating bath containing sodium hypophosphite as a reducing agent. The chemical plating forms a composite film having the particles or fibers codeposited and dispersed in the nickel matrix. In order to enable the dispersion of the particles or fibers in the bath and the code position of the particles or fibers from such an electroless plating bath having a sodium hypophosphite reducing agent, surface active agents must be added to the bath. These surface active agents, however, can lead to the formation of electroless composite films having an irregular color tone stripe, particularly when fluorinated particles or fibers are codeposited.
In order to increase the amount of particles or fibers that are codeposited in the composite film, there is not known any effective means other than increasing the amount of particles or fibers dispersed in the bath.